Portable keyboard



FIG. 1 is a front, right side, perspective view of a portable keyboard showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is a front, right side, perspective view in use state thereof;

FIG. 9 is a front view in use state thereof;

FIG. 10 is a rear view in use state thereof;

FIG. 11 is a left side view in use state thereof;

FIG. 12 is a right side view in use state thereof;

FIG. 13 is a top view in use state thereof; and,

FIG. 14 is a bottom view in use state thereof. 

CLAIM The ornamental design for a portable keyboard, as shown and described. 